Emergency services including the fire brigade and North East Ambulance service attended the incident on the A179 dual carriageway near Hart village at around 5pm on Friday, July 2.
One person from one of the vehicles was taken to hospital after the fire brigade had to cut the doors off to rescue them.
A spokesman for Cleveland Fire Brigade said: “We got called at 17.00 from the ambulance service to a three vehicle RTA and fuel spillage.
"The fire brigade made the vehicles safe and contained the fuel and oil spill.
"We cut the doors off one vehicle and assisted the casualty out. They were taken to hospital by ambulance.”
A number of other people involved described as walking wounded were checked by paramedics and also went to hospital for checks.